This invention relates in general to embroidery machines and in particular to a new and useful support for embroidery frame holders for receiving pins fastened on tongues of the embroidery frame and which may be fixed by locking means.
In German utility model No. 78 23 992, a device for the attachment of several embroidery frames on multi-head embroidering machines is shown. Each embroidery frame is equipped with two frame holders spaced from each other, each carrying a lock pin. One of the two lock pins is inserted in a fixed hook, the other in a spring loaded catch hook pivotable about a bearing stud. The catch hook is provided with a release arm, the front face of which is formed as a lead-in cam for the lock pins of the embroidery frames. The fixed hooks and catching hooks are connected with bearing blocks arranged at the frame guide. The disadvantage of the described device is that each embroidery frame must be locked individually. In embroidery machines with several embroidery points to be worked simultaneously this resultes in a complicated and time consuming changing of the individual frames.
In Swiss Pat. No. 29,577 a clamping device on cloth frames of embroidering machines for simultaneous actuation of two clamping rods from a single point is disclosed. The axle of a handle is pivotably arranged in a bearing secured on a cross-beam of the cloth frame and serves, in addition, to receive a lever controllable with the handle, which lever is connected at both sides via rods and angle pieces with the clamping rods that receive and clamp a strip of cloth. The individual rods and angle pieces of the arrangement are connected together by joints.
By turning the handle a movement is produced and transmitted via the linkage to the clamping rods, which, by their shifting movement, uniformly tension the clamped cloth strip. After completed clamping, a ratchet holds the device in clamped position. After the cloth has been embroidered, it is released and the embroidered portion is wound up on one of the two beams.
In the above described device, a linkage is provided for the transmission of the movement necessary for the clamping process. This results in a heavy construction which requires much space. Besides, the numerous joints for interconnection of the rods cause play (slip) in the movement transmission.